Electrolytic light source



J. COULSON.

- ELECTBOLYTIC LIGHT SOURCE. APPLICATION man Nov.3, 19u.

1,419,360, PawnaJune 13, 1922.

WITNEssEs: INVENToR v l :l0/171. Cou/son .UNITED STATES PATENT OFFICE.

JOI-IIS' COULSON, OF VIIL'KINSB'URG, PENNSYLVANIA., ASSIGNOR 'IO *NESTING'HOUSE i ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF IEENNSYLVANIA.

ELECTRO LYTIC LIGHT SOURCE.

Specification of Letters Iatent.

Patented J une 13, 1922.

Application filed November 3, 1917. Serial No. 200,042.

l/"o all whom t may concern:

Be it known that l', doi-1N Courson, a subject of the King oi (ireat Britain, and a resident of llv/Yilkinsburg. in the county ot Allegheny and State of Pennsylvania, have invented a new and useful Improvement in llllectrolytic Light Source, oi which the `tollowing is a specification.

My invention relates to the production oi.l light, and it has for an object to produce iight directly trom electro-chemical energy.

Another object ot my invention is to pro-- duce light without the production olI a large amount oit heat.

Another object of my invention is to produce a source of light that may be safely operated in the presence oi explosive gases and atmospheres.

Another object of my invention is to produce a source of light that may be simply and easily constructed.

Another object of my invention is to produce a source of light that may be operated upon electric circuits in which there are large vfluctuations of voltage.

A further object of my invention is to produce a source of light that may yield light having particularly desirable qualities and characteristics.

A still further object ot my invention is to produce a source of light that may be reliable and economical in operation.

I have discovered that, under certain conditions. plates of various metals may be made to emit light when subjected, in a bath, to the action of an electric current.

In the drawing, Fig. l is a vertical sectional view of a source of light constructed in accordance with my invention for directcurrent energization; Fig. 2 is a. corresponding view of a source of light designed for alternating-current energization; Fig. 3 is an elevational view of a tubular lamp constructed according to my invention; Fig. 4l is a sectional view, on an enlarged scale, taken on lines lV-IV of Fig. and Fig. V) is a sectional view ot a modification ot the tubular form of lamp.

In Fig. l, a source oli light l consists ot two electrodes 2 and 3, suspended in an aqueous hath. 4 in a transparent container 5. Electrode 2, which may be of aluminum alloyed with manganese or manganese and copper, is connected, as an anode, through a variable resistance element 19, to the positive terminal. of a direct-current battery 6. the negative terminal of which is connected to electrode 8, which may be ot carbon or aluminum or other metal or substance which not soluble in the aqueous bath 4. The hath 4. may contain various compounds commonly used as eicctrolytes, such as citric acid or the citrate, carbonate, berate or bitartrate of ammonia.

In operation, electric current is passed from one electrode to the other through the electrolyte, and a 'film 7 ot aluminum hydroxid, the thickness ot which is exaggerated in the drawing, is lormed upon the surface of the positive electrode 2. lt advisable to regulate the temperature ot the bath and the strength of the electric current duringthe film-forming operation in order to secure a uniform deposit of hydroxid over the entire surface of the Iilming electrode. After theiilin has been formed, 'the source of light l. is subjected to an electromotive force which may vary from below volts to above 400 volts. The electrode 2 soon begins to glow and gives ott' a considerable quantity of light. Its appearance is much like that of a piece of heated iron which is cooling oit' from the white to the yellow stage. With higher current density, a bright sparkling eii'ect'begins to appear "over the entire surface of the luminous electhis sparkling;r condition, as the late is strongly luminous before spark mg is noticeable. In the case of aluminum alloyed with both manganese and copper, the light emitted has a peculiar bluish tinge, probably caused by some reaction in which the copper is involved.

In Fig. 2, is shown a form of my invention in which electrodes 8 and 9, connected to the terminals of ay source 10 oi' alternating-current, are suspended in an aqueous bath l1 in a transparent container 12. In this form oit the invention, a film is formed upon each of the electrodes 8 and 9 by independently subjecting them to the treatment described in connection with the formation of film 7 upon electrode 2. Electrodes 8 and 9 are then assembled and connected as shown. The operation is, in all essentials, the same as that described in connection with Fig. l, except that the elec- Adesired or Well-known means for supporting the electrodes may be employed.

Vhile l am not preparedto sta-te the exact theory of the phenomona involved, it would appear that the electrical energygives rise to chemical reactions at the surface of the positive electrode which set yup vibrations Within the range of light Waves at the surface of the electrode.

It appears that the quantity'of light is'a function of the current density at the surface of the electrodes. The quantity of light depends also upon the composition of the luminous electrode and, in the case of aluminum alloyed with manganese, the quantity of light increases With increase in the proportion of manganese in the alloy.

.It Will be seen that this invention has a Wide range of applications in the industries, since the conversion from electro-chemical or chemical energy, as the case may be, to light energy, is accomplished Without production of heat. It is, therefore, possible to operate a lamp of this character in locations Where heat production is undesirable or even dangerous. The emitted light appears to be of particularly lgood quality. Since heat loss, which occurs in the ordinary method of producing light by means of incandescent substances, is largely avoided, it should be possible, by using suitably designed lamps according to my invention, to secure very much higher eficiency in the conversion of electrical energy to light energy than has heretofore been obtained.

While I have illustrated several conventional forms which my invention may take, it is to be understood that the structure and materials which I have specifically described may be variously modified by those skilled in this or related arts without exceeding the limits of my invention, which is, therefore, to be restricted only by the scope of the appended claims.

I claim as my invention:

l. A light-producing device including` a plurality of film-forming electrodes formed of an alloy comprising aluminum, manganese and copper, a suitable electrolyte surrounding the electrodes and a transparent container therefor.

2. A light-producing device including a plurality of film-forming.electrodesformed of an alloy comprising aluminum and manganese, a suitable electrolyte surrounding the electrodes and a transparent container therefor.

'In testimony whereof, I have hereunto subscribed my name this 22nd day of Oct.,

JOHN COULSON. 

